Circuit breaker



Jan. 14, 1941. J. H. HELLAND 2,228,956

CIRCUIT BREAKER Filed June 1, 1938 IN V EN TOR.

BY I

ATTORNEYS.

Patented Jan. 14, 1941 UNITED STATE CIRCUIT BREAKER John H. Helland,Newark, Ohio, assignor of onethird to William M. Pearson, Ncwark,-0hioApplication June 1, 1938, Serial No. 211,300

2 Claims.

This invention relates to circuit breakers, and particularly to circuitbreakers of the automati cally controlled type, the primary object ofthe invention being to provide a circuit breaker for use in the usualfuse plug socket, the device being so constructed that an overloadcurrent will automatically cause the operation of the de vice to breakthe circuit in which the circuit breaker is positioned, therebyprotecting the line and appliances connected therein.

An important object of the invention is to provide a device of thischaracter which will be sen sitive to abnormal heat caused by anoverload current passing through the device.

A further object of the invention is to provide a circuit breaker whichwill operate instantaneously, and one which must be returned to itsoperative or reset position by an attendant, thereby preventing theoperation of the device until the abnormal condition causing theoverload current, has been corrected.

With the foregoing and other objects in view, which will appear as thedescription proceeds, the

invention resides in the combination and arrangement of parts and in thedetails of construction hereinafter described and claimed, it beingunderstood that changes in the precise embodiment of the inventionherein described, may be made within the scope of what is claimed,without departing from the spirit of the invention.

Referring to the drawing:

Figure 1 is a longitudinal sectional view through a circuit breakerconstructed in accordance with the invention.

Figure 2 is a transverse sectional view taken on line 22 of Figure 1.

Figure 3 is a transverse sectional view taken on line 3-3 of Figure 1.

Referring to the drawing in detail, the housing or body portion of thecircuit breaker is indicated generally by the reference character 5, thelower end of the housing being closed by the disk-like member 6,constructed of suitable insulating material, and held to the housing orbody portion 5, by means of the screw shell 1, which is formed with anannular inwardly extended flange 8 that engages the disk-like member,and holds the disk-like member against one end of the housing or bodyportion.

Supported by the disk-like member 6, is the stationary contact member 9of the circuit breaker, which is normally in contact with the movablecontact member l0 carried at the lower end of the threaded rod I I, thecontact member ID being in the form of a cap, threaded on the lower endof the rod l I.

As shown, the threaded rod H' is hollow and supports the expansibledisk-like member l2 at its upper end, the member I2 being incommunication with the hollow threaded rod and adapted to contain etheror other suitable liquid which will expand under the action of heat.

The member I 2 is connected with the member l3 which embodies a lengthof flat steel spring material that has its ends held within the groovel4 formed in theliner l5 constructed of iron held within the housing orbody portion 5. The length of the member i3, is such that whenpositioned within the groove H, the member I3 is bowed. When the memberi3 is bent downwardly, as shown by Figure 1 of the drawing, the contactmember I0 is engaging the stationary contact member 9. It is obviousthat when the member l3 moves upwardly, and the member l3 snaps pastdead center, the movable contact member ill will be moved away from themember 9, breaking the circuit.

Mounted on the threaded rod l I, is a spoollike piston l6 constructed ofiron which provides a support for the resistance coil I! which is woundtherearound. One end of the electromagnetic coil i'l connects with themovable contact member ill, at I8, the opposite end of theelectromagnetic coil i'l indicated at i9, extends through the insulatingmember of the piston Hi from where it passes between the lower end ofthe piston l6 and disk-like member 6, and connects with the copper strip2| that extends along the housing 5 and connects with the screw shell I.The cover for the housing or body portion 5 is indicated by thereference character 22, and is constructed of suitable insulatingmaterial such as Bakelite or the like. This cover 22 is formed with acentral opening in which the push button 23 extends, the push button 23being designed to engage the spring member i3, to return the springmember to its normal active position, after it has been actuated tobreak the circuit.

Ventilating openings indicated at 24 are formed in the cover 22 andpermit of a circulation of air through the housing or body portion.

Due to the construction shown and described, it will be seen that thecontact member ID will rest against the stationary contact member 9,completng the circuit to the circuit breaker, under normal conditions.Should an overload occur, it is obvious that the electromagnetic coil I!will become heated, with the result that the ether or liquid containedin the rod it and'expansible disk-like member It, will become heated,

move away from the contest member 9, breaking the circuit through thehousing or hody portion 5.

In order to reset the circuit breaker, it is only necessary to press thebutton 23 downwerdly against the member it, until the member is reevespast dead center end snaps to its active or operative position,

It might be further stated that due to the construction of the rod. iii,the piston, and contact member it may be adjusted with respect theretoto insure a true operation of the circuit breaker.

I claim:

l. A circuit breaker comprising a housing, a threaded shell on thehousing and adapted to be positioned in a standard socket, contactingstetionary and movable contact members in the housing, a thermal elementwithin the housing. a hollow rod movable with the thermal element and onwhich the movable contact member is secured, said rod and thermalelement containing ether, a coil within the housing and in ciroverloadcurrent, expanding the thermal element and operating the rod whereby thecircuit between the contact members is broken.

2. A circuit breaker comprising a. housing, a threaded shell on thehousing and adapted to be positioned in a standard socket, a stationarycontact member disposed at one end of the housing, a length of fiatspring steel material normally bent past dead center, mounted within thehensing, a thermal element mounted within the housing, and beingconnected to the length of flat steel material at a. point intermediatethe ends thereof, said thermal, element comprising a hoilow rod and anexpansible member connected to the rod, a, stationary contact membersecured at one end of the casing, a, movable contact member secured toone end of the rod and engaging with the stationary contact membercompleting a circuit, said thermal clement containing ether, a. coilmounted on sold hollow tube and being in circuit with the shell andmovable contact member, said coll adapted to heat the ether in thethermal element under an overload. current, expanding the thermalelement, breaking the cir cultbetwecn the contact members, and saidlength of spring steel material adapted to bend past dead center in theopposite direction, holding the contact members separated.

JOHN H. HELLAND.

